Kinetics of Tungstate and Phytate Adsorption by D201 Resin

Leaching of scheelite ore with phytate is a novel and clean hydrometallurgical method of isolating tungsten, which achieves efficient decomposition under atmospheric pressure. However, realizing the separation and recycling of tungstate and phytate has become an additional and subsequent problem, which had not been encountered in the traditional tungsten metallurgical process. In determining ways to overcome this obstacle, ion exchange methods exhibit promising routes to separate tungstate and phytate. Before performing this new method, it is prudent to study the kinetics of the ion exchange process. The effects of WO3 concentration, phytate concentration, resin particle size, and reaction temperature were investigated. Results show that a pseudo-second-order model can describe the adsorption kinetic behavior of phytate and tungstate in the mixed solution. The apparent activation energies of WO3 and phytate, based on the Arrhenius expression, were calculated as 21.4 kJ/mol and 21.8 kJ/mol, indicating that the adsorption processes of phytate and tungstate are diffusion-controlled.